I just ran into this problem exactly. Using 4.14.1. Shocking this hasn’t been fixed yet. Seems like most projects would run into this eventually.
We just came across this issue when trying to package our game in 4.16.2
I can tell you that our actors do spawn because I can see their shadows on the ground. But the AI mesh is invisible, however in version 4.15 I did not have this problem.
Please help!